Rhinoceros Hornbill

(Buceros rhinoceros)


The word "rhinoceros" is of Greek origin -- "rhino" meaning "nose", and "ceros" meaning "horn." This means that the Rhinoceros Hornbill's name could be translated to "Nose Horn Hornbill!"

If you were to mistake the Rhinoceros Hornbill for some sort of prehistoric dinosaur, you wouldn't be alone.  This big, mostly black bird has more in common with dinosaurs than just feathers and fierce, staring eyes.  As one of the largest hornbills, the Rhinoceros Hornbill also has one of the largest and most impressive casques -- a feature they share with hadrosaurids from more than 60 million years ago.

A casque is the large head ornamentation that looks almost like a second bill atop a hornbill's head, and is what inspired the Rhinoceros Hornbill's common name.  Both male and female hornbills have casques, so while the male's is often just a little bit bigger, that isn't a fool-proof way to tell the sexes apart.  (The best way is to look at their eyes:  males have mahogany red eyes, while the female's eyes are white.)  The hornbill's casque is formed from the same material as your fingernails (keratin), and can take up to six years to fully develop.  Also like your fingernails, the Rhinoceros Hornbill's beak and casque are naturally white.  Throughout the bird's lifetime, it rubs its beak and casque against an oil gland under its tail to gradually produce the glossy red-yellow-orange color that's so striking in adult birds.

The Rhinoceros Hornbill's casque isn't just about looking handsome, though.  The structure is mostly  hollow, and is thought to amplify the hornbill's calls so they can be heard all throughout the Indonesian rainforest.  This feature has led paleontologists to believe that maybe harosaurs used their fancy head crests in the same way.  So when you hear a Rhinoceros Hornbill's echoing honk from somewhere out of sight, you might just be hearing the voice of this great bird's inner dinosaur.


Indonesia, Asia, into southern Thailand.




Fruit (especially figs) and occasional small mammals and reptiles.


Rhinoceros Hornbills (like other hornbills) practice one of the most ingenious nesting rituals of any bird. When the female is ready to lay her eggs, she goes into a hollow tree cavity and helps the male seal the entrance with a paste made of fruit, mud, and feces. The pair leaves only a small slit, through which the male feeds the female (and later the chicks) for the next four to five months. The female keeps the inside of the nest cavity clean by pushing uneaten food and fecal matter back out through the same slit. When the chicks are about three months old, the female breaks herself out -- and both parents and offspring collaborate to re-seal the chicks inside for another three months. Both parents continue to care for the chicks until they are old enough to break out of the nest on their own and fly free.


Near Threatened

At the Aviary

The National Aviary is home to a female Rhinoceros Hornbill. She currently lives behind the scenes.